WO2020149397A1

WO2020149397A1 - Rod-type electrical cylinder

Info

Publication number: WO2020149397A1
Application number: PCT/JP2020/001446
Authority: WO
Inventors: 横山　進二; 博幸金丸
Original assignee: 平田機工株式会社
Priority date: 2019-01-18
Filing date: 2020-01-17
Publication date: 2020-07-23
Also published as: JP7090565B2; JP2020118168A

Abstract

This rod-type electrical cylinder (10) is provided with a cylinder body (11) with one end an open end (11b) and the other end a closed end (11a), a cylinder rod (12) which is provided in the cylinder body and which can project out of and disappear back into the open end, a support member (13) which is detachably provided on the cylinder body, a drive unit (14) which is provided on the support member and which supplies drive power for driving the cylinder back and forth, and a driven member (15) which transmits drive power of the drive unit to the cylinder rod.

Description

Rod type electric cylinder

The present invention relates to a rod-type electric cylinder that advances and retracts a cylinder rod by a driving force of an electric motor.
The present application claims priority based on Japanese Patent Application No. 2019-007190 filed in Japan on January 18, 2019, the content of which is incorporated herein by reference.

In recent years, due to the declining birthrate and aging population, a labor shortage has become a problem at production sites. In order to eliminate this labor shortage, automation of machine tools is being promoted. The bottleneck (obstacle) in this automation is the automatic opening and closing of the door (door part) of the machine tool that supplies and takes out parts. Currently, air cylinders and electric cylinders are known as equipment for automatically opening and closing doors. By moving the cylinder rod of the cylinder back and forth, the door of the machine tool is automatically opened and closed.
Since the electric cylinder is naturally airless, it is superior to the air cylinder in energy saving and equipment cost, but in the case of the rod type electric cylinder, the maximum cylinder stroke is about 600 to 800 mm. Therefore, in the case of a long rod type cylinder having a stroke length exceeding 1000 mm, the air cylinder is currently selected.
By the way, some air cylinders include a disassembled type that can be disassembled and a non-disassembled type that is not. In the air cylinder, when the rubber packing inside the air cylinder wears over time, the cylinder rod does not move back and forth smoothly.

At this time, for the non-disassembly type air cylinder, replace the entire air cylinder itself. On the other hand, in the disassembly type air cylinder, it is possible to disassemble the air cylinder and replace only the worn packing (sliding contact portion). After that, it is reassembled and used. However, even in the disassembled air cylinder, since the rod is normally driven while the air is sealed, the air cylinder has an airtight structure, which cannot be said to be a structure considering disassembly and assembly. That is, even though it is a disassembled air cylinder, its disassembling/assembling property is not good.

▽ Here, a linear drive structure is known in which the rectangular rod is moved linearly by driving the electric motor to wind and drive the timing belt. The rectangular rod is supported by a supporting portion (supporting member) so as to be linearly movable via a sliding contact portion (see Patent Document 1). There is also known an actuator that rotates a ball screw with an electric motor to move the ball nut along the ball screw to move a tubular rod (hereinafter referred to as a cylinder rod) together with the ball nut. The ball nut is housed inside the cylinder rod (see Patent Document 2).

Japanese Unexamined Patent Publication No. 9-229153 Japanese Patent Laid-Open No. 2001-132810

However, although the linear drive structure of Patent Document 1 is a structure similar to a cylinder, the one that is moved back and forth is a square rod, and is not a standard round rod as a rod-type cylinder. Therefore, it is not easy to replace the existing rod type air cylinder with this linear drive structure. In other words, it may not be possible to use the accessory of the existing air cylinder.
In addition, in the actuator of Patent Document 2, the ball nut and the cylinder rod are moved back and forth, and the volume of the moved one is large. Since the cylinder rod becomes longer as the stroke of the cylinder rod advances and retracts, the weight of the motor moving back and forth increases accordingly. For this reason, if the stroke of the cylinder rod is lengthened, it is difficult to drive with a small capacity electric motor, and a large capacity electric motor (that is, a large electric motor) is required. However, it is difficult to replace an electric cylinder using a large electric motor with, for example, an air cylinder for automatically opening and closing a door of a machine tool. This is because the existing air cylinder is naturally air-driven and therefore does not include an electric motor, and the installation space for a large electric motor is not considered. Therefore, it is not easy to replace the existing long rod type air cylinder with the electric cylinder.
Further, most cylinder rods of air cylinders are made of solid carbon steel. Also in the air cylinder, since the rod weight becomes heavier as the cylinder stroke becomes longer, when the rod is moved forward, "deflection (= sag)" is inevitably generated. This phenomenon is difficult to avoid even if the rod diameter is reduced in order to reduce the weight of the rod, because the rigidity decreases as the rod becomes thinner.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rod-type electric cylinder that can secure a long stroke length of a cylinder rod and that is easy to disassemble and assemble the cylinder rod.

A rod-type electric cylinder according to one aspect of the present invention includes a cylinder body having one open end and the other closed end, a cylinder rod provided in the cylinder body and retractable from the open end, and the cylinder body. A support member that is detachably provided; a drive unit that is provided on the support member and that supplies a driving force that drives the cylinder rod forward and backward; and a driven member that transmits the driving force of the driving unit to the cylinder rod. It is a rod type electric cylinder provided with.

In the rod type electric cylinder of the one aspect of the present invention, the cylinder rod has a groove extending in a longitudinal direction in a part of a peripheral surface thereof, and the groove is provided with a timing belt as the driven member, A timing pulley provided in a drive unit may be meshed with the timing belt to drive the cylinder rod forward and backward.

In the rod type electric cylinder according to the one aspect of the present invention, a ball screw nut as the driven member is provided in the vicinity of the opening end of the tubular body, and a driving force transmitting unit provided in the drive unit and the ball are provided. The cylinder rod may be driven forward and backward by engaging with a screw nut.

In the rod type electric cylinder of the one aspect of the present invention, a rack as the driven member extending in the longitudinal direction is provided on a part of the peripheral surface of the cylinder rod, and a pinion provided in the drive unit, and the rack. May be engaged to drive the cylinder rod forward and backward.

In the rod type electric cylinder of the one aspect of the present invention, a magnet long piece as a driven member in which magnetic poles are alternately arranged along a longitudinal direction is provided on a part of a peripheral surface of the cylinder rod, and the drive unit is provided. It is also possible to drive the cylinder rod forward and backward by non-contact transmission between the magnet gear having the magnetic poles alternately arranged along the circumferential direction and the magnet long piece.

In the rod type electric cylinder according to the one aspect of the present invention, the rod type electric cylinder is provided at least at an open end in the cylindrical body, holds the cylinder rod at the center of the cylindrical body, and assists sliding of the cylinder rod accompanying forward/backward drive. And a guide member.

In the rod type electric cylinder according to the aspect of the present invention, the guide member includes a fixed guide provided at an open end in the cylinder body, and a moving guide provided in the cylinder body and at a rear end of the cylinder rod. , May be provided.

In the rod type electric cylinder according to the aspect of the present invention, the support member may include a split fastening portion, and the tubular body may be inserted into a split fastening hole in the split fastening portion.

According to the present invention, a long stroke length of the cylinder rod can be secured, and further, a rod-type electric cylinder having good disassembly and assembly of the cylinder rod can be obtained.

It is a side view which shows the state which attached the rod type electric cylinder of 1st Embodiment which concerns on this invention to the machine tool. It is sectional drawing which shows the rod type electric cylinder of 1st Embodiment. It is a perspective view showing a rod type electric cylinder of a 1st embodiment. FIG. 4 is a sectional view taken along line IV-IV in FIG. 1. It is a perspective view explaining the state where the split fastening part of 1st Embodiment was attached to the open end of the cylinder. It is a perspective view explaining the state which removed the open end of the cylinder from the split fastening part of a 1st embodiment. It is sectional drawing which shows the movement guide provided in the rear end of the cylinder rod of 1st Embodiment. It is a top view showing the state where the 3rd mounting bracket was provided in the front end of the cylinder rod of a 1st embodiment. It is sectional drawing which shows the rod type electric cylinder of 2nd Embodiment which concerns on this invention. It is sectional drawing which shows the rod type electric cylinder of 3rd Embodiment which concerns on this invention. It is sectional drawing which shows the rod type electric cylinder of 4th Embodiment which concerns on this invention. It is sectional drawing which shows the rod type electric cylinder of 5th Embodiment which concerns on this invention.

An embodiment of the rod type electric cylinder 10 according to the present invention will be described below.
(First embodiment)
As shown in FIG. 1, in the rod type electric cylinder 10, as an example, a cylinder 11 is attached to a machine tool (operated member) 1, and a cylinder rod 12 protruding and retracting from the cylinder 11 is a door portion 4 of the machine tool 1. And is used as an actuator for automatically opening and closing the door 4. In the first embodiment, an example in which the rod type electric cylinder 10 automatically opens and closes the door portion 4 of the machine tool 1 will be described, but the rod type electric cylinder 10 can also be applied to other applications.

The rod type electric cylinder 10 includes a cylinder body 11, a cylinder rod 12, a support member 13, a drive unit 14, and a timing belt (driven member) 15. In the following description, the side on which the tubular body 11 is provided is the upper side, and the side on which the casing portion 2 described later is provided is the lower side. The side on which the cylinder rod 12 is provided is the front side, and the side on which the tubular body 11 is provided is the rear side. Further, the radially outer side and the radially inner side of the cylinder rod 12 may be simply referred to as the outer peripheral side and the inner peripheral side.
The closed end 11a and the open end 11b of the cylinder 11 are attached to the top 2a of the casing 2 of the machine tool 1 via the first mounting bracket 17 and the second mounting bracket 18, respectively. The front end 12 a of the cylinder rod 12 is attached to the top portion 4 a of the door portion 4 of the machine tool 1 via the third attachment bracket 19. By moving the cylinder rod 12 of the rod type electric cylinder 10 back and forth, the door 4 of the machine tool 1 is automatically opened and closed.

As shown in FIGS. 1 and 2, the tubular body 11 is formed in a tubular shape, and has a closed end 11a closed on one side in the longitudinal direction and an open end 11b opened on the other side. The first attachment bracket 17 is attached to an end portion including the closed end 11a, and the first attachment bracket 17 is attached to one end 2b of the top portion 2a of the casing portion 2. The support member 13 is detachably attached to an end portion including the open end 11b.

As shown in FIGS. 3 and 4, the support member 13 includes a support mounting portion 24 and a motor bracket 25. The support mounting portion 24 includes a split tightening portion 26, a connecting portion 27, and a fitting portion 28.
The split fastening portion 26 has a tubular main body portion 32 and a fastening portion 33 extending upward from the main body portion 32. The body portion 32 and the fastening portion 33 are integrally formed. The main body 32 includes a split hole 31 formed in a circular shape. The fastening portion 33 has a slit 37 that extends from the top portion 33 a to the inner peripheral surface 31 a of the split fastening hole 31.
The slit 37 divides the fastening part 33 into a first half part 38 and a second half part 39. A split tightening bolt 41 is inserted through the first half-split portion 38 and the second half-split portion 39, and the first half-split portion 38 and the second half-split portion 39 are split by the bolt 41.

As shown in FIG. 5A, in the state where the opening end 11b of the tubular body 11 is inserted into the split tightening hole 31 of the split tightening portion 26, by tightening the split tightening bolt 41, the first half split portion 38 and the second half split portion. The interval between the slits 37 between the split portions 39 is narrowed, and the split tightening hole 31 is reduced in diameter. As a result, the inner peripheral surface 31a of the split tightening hole 31 tightens the end portion of the tubular body 11 on the open end 11b side, and the support member 13 is fixed to the tubular body 11.

Further, as shown in FIG. 5B, by loosening the split tightening bolt 41, the interval of the slit 37 between the first half-split portion 38 and the second half-split portion 39 is expanded, whereby the inner circumference of the split tightening hole 31. The tightening of the end portion of the cylindrical body 11 on the open end 11b side by the surface 31a is released. As a result, the open end 11b of the tubular body 11 can be pulled out from the split tightening portion 26. As described above, the end portion including the open end 11b of the tubular body 11 can be provided so as to be freely inserted into and removed from the split fastening portion 26.

As shown in FIGS. 2 and 3, the connecting portion 27 is integrally formed with the main body portion 32 of the split fastening portion 26. The connecting portion 27 is formed in a C-shape (arch shape) in cross section whose upper side is open, and has a connecting opening 43 at a portion corresponding to the fastening portion 33. The fixed guide 46 is arranged on the inner peripheral surface 27 a of the connecting portion 27. In other words, the fixed guide 46 is provided so as to face the opening end 11b in the cylindrical body 11 via the support member 13. The fixed guide 46 constitutes a guide member 45 together with a moving guide 47 (described later in FIG. 6).

The fixed guide 46 has a C-shaped cross section (arch shape) having an opening in a portion facing the connection opening 43 (upper portion in FIG. 2). Further, the fixed guide 46 has a two-layer structure including a fixed main body portion 46a and a fixed sliding contact portion 46b. The fixed main body portion 46 a is provided on the inner peripheral surface 27 a of the connecting portion 27. The fixed sliding contact portion 46b is detachably provided on the inner peripheral surface (inner peripheral side) of the fixed main body portion 46a, and is made of non-lubricating resin. By the fixed sliding contact portion 46b, the friction when the cylinder rod 12 is driven back and forth is kept small, and the cylinder rod 12 is supported with good straightness. Further, since the fixed guide 46 is formed in an arcuate cross section, the fixed sliding contact portion 46b of the fixed guide 46 can be easily accessed through the opening. As described above, in the fixed guide 46, only the fixed sliding contact portion 46b, which is a consumable item, can be easily replaced, so that the cost of replacing the parts can be suppressed as compared with the case where the fixed guide 46 is entirely replaced. it can.

Here, a belt groove 51 (see also FIG. 4) is formed in the cylinder rod 12. The cylinder rod 12 is arranged such that its circumferential position is defined so that the belt groove 51 faces the connection opening 43. Then, at least a part of the outer peripheral surface 12c of the cylinder rod 12, more specifically, a part of the cylinder rod 12 whose circumferential position is defined as described above except the belt groove 51, is fixed by the fixed guide 46 described above. Surround and support. As a result, the fixed guide 46 does not hinder the forward/backward drive of the cylinder rod 12.
The fixed guide 46 may be formed to have an annular cross section and to support the entire outer peripheral surface 12c of the cylinder rod 12. In this case, it is preferable that the fixed guide 46 is arranged in the cylindrical body 11 near the opening end 11b. At this location, the fixed guide 46 does not interfere with the belt groove 51 of the cylinder rod 12 and the timing belt 15 arranged in the belt groove 51. The fixed guide 46 may be arranged at any position where the fixed guide 46 does not interfere with the belt groove 51 and the timing belt 15, and is not limited to the vicinity of the opening end 11b in the tubular body 11.

The connecting portion 27 has a pair of

walls

27b and 27c parallel to the axis of the cylinder rod 12. The space between the

walls

27b and 27c forms the connection opening 43. A first bearing portion 53 and a second bearing portion 54 are provided upright on the upper portions of the

wall portions

27b and 27c at intervals in the longitudinal direction (axial direction) of the cylinder rod 12. That is, the first bearing portion 53 and the second bearing portion 54 are erected on the upper portion of the wall portion 27b, and the other first bearing portion 53 and the second bearing portion 54 are erected on the upper portion of the wall portion 27c. Has been done.
The first bearing portion 53 of the one wall portion 27b and the first bearing portion 53 of the other wall portion 27c have concentric and first support holes 55 of the same diameter, respectively. The first support shaft 56 is supported by the pair of first support holes 55. A first idler pulley 86 (described later) is rotatably supported between the

first bearing portions

53, 53 of the first support shaft 56. The lower end portion of the first idler pulley 86 faces the belt groove 51 in the cylinder rod 12 that faces the connection opening 43.

Also, the second bearing portion 54 of the one wall portion 27b and the second bearing portion 54 of the other wall portion 27c have concentric and second support holes 57 of the same diameter, respectively. The second support shaft 58 is supported by the pair of second support holes 57. A second idler pulley 87 (described later) is rotatably supported between the

second bearing portions

54, 54 of the second support shaft 58. The lower end portion of the second idler pulley 87 faces the belt groove 51 similarly to the first idler pulley 86.

The motor bracket 25 is erected on the first bearing portion 53 and the second bearing portion 54 of the one wall portion 27b. The motor bracket 25 may be provided separately from the first bearing portion 53 and the second bearing portion 54 as described above, but may be provided integrally with the first bearing portion 53 and the second bearing portion 54.
The motor bracket 25 has an axially elongated hole extending in the vertical direction. A motor unit 84 is provided on the surface of the motor bracket 25 opposite to the surface facing the connection opening 43. The drive shaft 91 of the motor unit 84 is inserted into the shaft long hole, and the motor unit 84 is supported by the motor bracket 25 by the first to fourth adjustment bolts 61 to 64. The drive shaft 91 projects from the surface of the motor bracket 25 that faces the connection opening 43. By changing the insertion position of the motor unit 84 with respect to the shaft long hole of the motor bracket 25, the relative positions of the motor unit 84 and the motor bracket 25 in the vertical direction can be changed.
A timing pulley 85 (described later) is attached to the protruding portion of the drive shaft 91. The motor bracket 25 includes a position adjusting unit 66. The position adjusting portion 66 has a first adjusting elongated hole 66a and a second adjusting elongated hole 66b formed on both sides of the axial elongated hole, through which the drive shaft 91 is inserted, in the longitudinal direction (axial direction) of the cylinder rod 12. Have. The first adjustment elongated hole 66a and the second adjustment elongated hole 66b extend in the vertical direction.

The first adjustment bolt 61 and the second adjustment bolt 62 are passed through the first adjustment slot 66a to fix the motor bracket 25 and the motor unit 84. Similarly, the third adjustment bolt 63 and the fourth adjustment bolt 64 are passed through the second adjustment slot 66b to fix the motor bracket 25 and the motor unit 84. As a result, the motor unit 84 is supported on the motor bracket 25 by the first to fourth adjustment bolts 61 to 64. With the first to fourth adjustment bolts 61 to 64 loosened, the motor unit 84 is moved up and down along the shaft elongated hole to separate the drive shaft 91 from the belt groove 51 in the motor unit 84. Can be adjusted. Thereby, the tension of the timing belt 15 can be adjusted.

A fitting part 28 is formed integrally with the connecting part 27. In other words, the support mounting portion 24 is fitted with the split tightening portion 26 on one end side (the left side in the drawings in FIGS. 2 and 3) of the connecting portion 27 and the other end side (the right side in the drawings in FIGS. 2 and 3). The part 28 is integrally provided. The fitting portion 28 is a disc member having the same outer shape (elliptical shape) as the split fastening portion 26, and has a circular fitting hole 68 therein. However, there is no notch such as a slit in a portion of the fitting portion 28 corresponding to the fastening portion 33 of the split fastening portion 26 (a portion above the fitting hole 68). The cap 71 is fitted in the fitting hole 68 of the connecting portion 27. The cap 71 is formed in a tubular shape and has a through hole 72. The cylinder rod 12 is inserted into the through hole 72 in a non-contact state.

The side of the cap 71 opposite to the side of fitting to the fitting portion 28 (the right side of the drawing in FIG. 2) is a small diameter portion via a step portion 71a, and this small diameter portion is formed in the male screw portion 74. ing. The second mounting bracket 18 is attached to the small diameter portion of the cap 71. The second mounting bracket 18 has a mounting hole 18a, and the small diameter portion is fitted into the mounting hole 18a. The second mounting bracket 18 is seated on the stepped portion (mounting surface) 71a. The nut 75 is screwed into the small diameter portion protruding from the mounting hole 18a. As a result, the stepped portion 71a and the nut 75 hold the stepped portion. As a result, the second mounting bracket 18 is fixed to the cap 71, and the second mounting bracket 18 is mounted to the rod type electric cylinder 10 via the cap 71.

Returning to FIG. 1, the second mounting bracket 18 is attached to the other end (the end on the side where the door 4 appears and disappears; the right end in the drawing in FIG. 1) 2c of the top 2a of the casing 2. Further, the first mounting bracket 17 is provided at the closed end 11a of the tubular body 11, and one end of the top part 2a of the casing part 2 (the end opposite to the end where the door part 4 appears and disappears. The left end of the drawing in FIG. 1). ) Attached to 2b. In this state, the tubular body 11 is arranged along the top portion 2a of the casing portion 2. The cylinder rod 12 is provided to be retractable from the opening end 11b of the tubular body 11.

As shown in FIG. 4, the cylinder rod 12 is made of, for example, a tubular body made of an aluminum alloy. When the cylinder rod 12 is most retracted, in other words, when the rod-type electric cylinder 10 is at the minimum length, the rear end (one end) 12b is located inside the cylindrical body 11 as shown in FIG. As shown in, the front end (the other end) 12 a is located slightly above the nut 75. A moving guide 47 (see FIG. 6) is provided at the rear end 12b of the cylinder rod 12. The constituent material of the cylinder rod 12 is not limited to the tubular body made of aluminum alloy, and may be, for example, a round rod (solid rod) made of aluminum alloy. Further, the cylinder rod 12 may be configured by a tube body or a round rod made of a material conventionally used as a structural light metal (or a light alloy).
The cylinder rod 12 has a belt groove (groove) 51 in a part 12d of the outer peripheral surface (circumferential surface) 12c. The belt groove 51 extends along the longitudinal direction (axial direction) of the cylinder rod 12 between the rear end 12b and the front end 12a. The belt groove 51 has, for example, a groove bottom portion 51a, a first wall portion 51b and a second wall portion 51c perpendicular to the groove bottom portion 51a. The timing belt 15 is laid on the groove bottom portion 51 a of the belt groove 51.

As shown in FIG. 6, the moving guide 47 is a member that constitutes the guide member 45 together with the fixed guide 46 (see FIG. 2), and is moved inside the tubular body 11 as the cylinder rod 12 is driven back and forth. It is in sliding contact with the inner peripheral surface of the cylindrical body 11. The moving guide 47 has a two-layer structure including a moving body portion 47a and a moving sliding contact portion 47b. The moving body portion 47a is formed of a disc body, and the rear end 12b of the cylinder rod 12 is inserted into the hole at the center thereof.
A moving sliding contact portion 47b is provided on the outer side (outer peripheral side) of the moving body portion 47a, and the moving sliding contact portion 47b is in contact with the inner peripheral surface of the tubular body 11. The moving sliding contact portion 47b is made of non-lubricating resin. The moving sliding contact portion 47b keeps the friction when the cylinder rod 12 is moved forward and backward, and supports the cylinder rod 12 with good straightness. The movable sliding contact portion 47b is formed of a ring body, and is provided on the outer peripheral surface (that is, the outer peripheral side) of the movable main body portion 47a so as to be attachable/detachable. As described above, the moving guide 47 can easily replace only the moving sliding contact portion 47b, which is a consumable item, so that the cost of parts replacement can be suppressed as compared with the case where the moving guide 47 is entirely replaced. it can.

As shown in FIGS. 2 and 6, the moving guide 47 and the fixed guide 46 form a guide member 45. The guide member 45 holds the cylinder rod 12 at the center of the tubular body 11 by the fixed guide 46 and the moving guide 47, and guides (assists) the forward/backward drive of the cylinder rod 12 to prevent sliding friction during the forward/backward drive. Reduce.
Further, by attaching the movement guide 47 to the rear end 12b of the cylinder rod 12, the belt end 15a of the timing belt 15 is attached to one end of the belt groove 51 (the rear end side of the cylinder rod 12; the left end in FIG. 6). Is fixed.

Here, as shown in FIG. 5B, by loosening the split fastening bolt 41 from the tightened state and removing the end portion of the tubular body 11 including the open end 11b from the split fastening portion 26, the rod-type electric cylinder 10 is configured with each component. Can be easily disassembled. Therefore, for example, as shown in FIG. 2 and FIG. 6, the guide member 45 is disassembled from the rod-type electric cylinder 10 and necessary members (for example, the fixed sliding contact portion 46b and the moving sliding contact portion 47b) of the guide member 45 are disassembled. Etc.) and the timing belt 15 etc. can be appropriately maintained or replaced. That is, since the maintainability of the rod-type electric cylinder 10 is good and it is easy to replace parts such as consumables, the life of the rod-type electric cylinder 10 can be extended.

As shown in FIGS. 1 and 7, the rod cap 78 is fitted to the front end 12a of the cylinder rod 12, and the other end of the timing belt 15 (the front end side of the cylinder rod 12. The right end in the drawing in FIG. ) 15b is fixed to the other end 51e of the belt groove 51. The rod cap 78 includes a cap portion 78a fitted to the front end 12a of the cylinder rod 12, and a round rod portion 78b protruding from the cap portion 78a. A ring-shaped collar member 79 is fitted to the round rod portion 78b, and is seated on the step between the cap portion 78a and the round rod portion 78b.

Male thread is formed on the round rod portion 78b. By fitting the third mounting bracket 19 to the round rod portion 78b and screwing the nut 81 onto the male screw, the third mounting bracket 19 is sandwiched between the collar member 79 and the nut 81. As a result, the third mounting bracket 19 is fixed to the front end 12a of the cylinder rod 12 via the collar member 79. By attaching the third mounting bracket 19 to the top portion 4a (specifically, the end portion 4b of the top portion 4a) of the door portion 4 of the machine tool 1, the front end 12a of the cylinder rod 12 and the door portion 4 are connected.

As shown in FIGS. 6 and 7, one end 15a of the belt is fixed to the rear end 12b of the cylinder rod 12, and the other end 15b of the belt is fixed to the front end 12a of the cylinder rod 12. In this state, the timing belt 15 is housed in the belt groove 51.
The timing belt 15 is laid so that the belt teeth 21 are located on the side of the belt groove 51 that faces the groove bottom portion 51a. The timing belt 15 is connected to the drive unit 14 (see FIG. 2) and transmits the drive force of the drive unit 14 to the cylinder rod 12.

As shown in FIGS. 2 and 3, the drive unit 14 is a unit that is provided on the support member 13 and supplies a drive force that drives only the cylinder rod 12 to move back and forth. Specifically, the drive unit 14 includes a motor unit 84, a timing pulley 85, and first and second idler pulleys 86 and 87.
The motor unit 84 includes an electric motor 88 and a speed reducer 89. As the electric motor 88, for example, a motor that can be driven by 24V DC can be used. By connecting the speed reducer 89 to the electric motor 88, the rotation speed and the rotation torque of the drive shaft 91 are appropriately set. A timing pulley 85 is coaxially attached to the drive shaft 91. The timing pulley 85 has pulley teeth 85a formed on the outer periphery thereof.

The first idler pulley 86 has a bearing 861 fitted in the inner peripheral portion thereof, and the first support shaft 56 is inserted into the bearing 861. Similarly, the second idler pulley 87 has a bearing 871 fitted in the inner peripheral portion thereof, and the second support shaft 58 is inserted into the bearing 871. The first idler pulley 86 and the second idler pulley 87 are rotatably provided with respect to the first support shaft 56 and the second support shaft 58. The first idler pulley 86 and the second idler pulley 87 are arranged on both sides of the timing rod 85 in the longitudinal direction (axial direction) of the cylinder rod 12, and are arranged with a slight gap in the vertical direction with the cylinder rod 12. Has been done.

The timing belt 15 is wound around the timing pulley 85, the first idler pulley 86, and the second idler pulley 87. The timing belt 15 has belt teeth 21 meshed with pulley teeth 85 a of the timing pulley 85. The back surface (that is, a flat surface) 15c of the timing belt 15 is pressed by the first idler pulley 86 and the second idler pulley 87.
That is, the belt teeth 21 of the timing belt 15 are pressed against the groove bottom portion 51a of the belt groove 51 by the first idler pulley 86 and the second idler pulley 87, and the belt teeth 21 and the groove bottom portion 51a are sufficiently meshed with each other. As a result, the "slip" between the timing belt 15 and the belt groove 51 does not occur. Therefore, the driving force of the electric motor 88 is reliably transmitted to the cylinder rod 12 via the timing belt 15.

Further, by loosening the first to fourth adjusting bolts 61 to 64, the relative position (mounting position) of the motor unit 84 with respect to the motor bracket 25 in the vertical direction can be changed. Thereby, the distance from the belt groove 51 to the motor unit 84 (specifically, the drive shaft 91) can be adjusted. Accordingly, the belt tension of the timing belt 15 can be adjusted appropriately.
In this state, by rotating the timing pulley 85 in one direction by the motor unit 84, the timing belt 15 is sequentially wound in one direction and is sequentially sent out. As the timing belt 15 is sequentially fed, only the cylinder rod 12 is fed in one direction while the belt teeth 21 and the groove bottom portion 51a of the belt groove 51 are sequentially meshed. As a result, the cylinder rod 12 is driven forward or backward with respect to the tubular body 11. Therefore, for example, when a general ball screw drive electric cylinder is compared with the rod type electric cylinder 10 of the present embodiment, the weight of the driven unit per unit length is smaller in the present embodiment. In other words, when the capacity of the electric motor 88 of the general ball screw drive electric cylinder and the electric motor 88 of the rod type electric cylinder 10 of the present embodiment are the same, the present embodiment can drive a longer cylinder rod. it can. As a result, the rod-type electric cylinder 10 of this embodiment can secure a longer stroke L1 (see FIG. 1) of the cylinder rod 12 as compared with a general ball screw drive electric cylinder.

The rod-type electric cylinder 10 is configured to drive the cylinder rod 12 forward and backward by the timing belt 15. Therefore, in the rod-type electric cylinder 10, the support member 13 and the drive unit 14 are common constituent members, and in addition to this, the long cylinder 11, the cylinder rod 12, and the timing belt 15 are prepared. Then, by cutting these long materials into desired lengths, it is possible to obtain a cylinder constituent member having an arbitrary stroke length. That is, the rod-type electric cylinder 10 of the present embodiment has various advance/retreat stroke lengths including a long stroke when compared with a general ball screw drive electric cylinder, although the number of required parts in stock is small. Can correspond to. Therefore, it is possible to obtain the rod-type electric cylinder 10 with excellent cost performance in a short delivery period.
Further, in the rod type electric cylinder 10 of the present embodiment, it is possible to use a low thrust specification electric motor 88 as the electric motor 88 in the motor unit 84. By using this motor, when an operator makes a light contact with the cylinder rod 12 which is being driven back and forth, the rotation of the motor is instantaneously stopped and the driving forward and backward of the cylinder rod 12 is stopped. That is, since the rod-type electric cylinder 10 of the present embodiment is a cylinder that is safe for workers, it is not necessary to provide a safety fence or an area sensor around the rod-type electric cylinder 10, and the safety-related device configuration is simple. It's cheap.

In this way, by ensuring a long forward/backward stroke L1 of the cylinder rod 12 and setting the thrust of the cylinder rod 12 to a low thrust, the rod-type electric cylinder 10 of the first embodiment can be installed in the door portion 4 of the machine tool 1. It can be used as a device that automatically opens and closes.
Here, the rod-type electric cylinder 10 does not require air supply equipment or air piping work, unlike an existing air cylinder, by electrifying the actuator of the cylinder (for example, DC 24V). Here, since a solenoid valve or the like is required at a place where the air cylinder is used, a 24V DC power line for controlling these is always provided.

Therefore, when replacing the existing air cylinder with the rod type electric cylinder 10 of the present embodiment, the existing power supply line can be used as a drive source of the electric motor 88, and new work of the 24 V DC power supply line and wiring work are not required. .. Further, the rod type electric cylinder 10 of the present embodiment is configured in the same manner as an existing air cylinder. Therefore, all the various accessories (first to third mounting brackets 17 to 19) for the existing air cylinder can be used for the rod type electric cylinder 10 of the present embodiment. Thereby, for example, the existing air cylinder (especially a long object) provided for automatically opening and closing the door 4 of the machine tool 1 is completely replaced by the rod type electric cylinder 10 of the present embodiment. Will be possible.

Further, according to the rod type electric cylinder 10 of the first embodiment, the end portion including the open end 11b of the tubular body 11 can be easily removed from the split tightening portion 26 by loosening the split tightening bolt 41 from the tightened state. it can. Maintenance and replacement are performed on the disassembled support member 13 and cylinder rod 12. Therefore, the rod-type electric cylinder 10 of the present embodiment has good maintainability and easy replacement of parts such as consumables, so that the rod-type electric cylinder 10 can have a long life.

Hereinafter, the rod type electric cylinders 100 to 130 of the second to fifth embodiments will be described with reference to FIGS. 8 to 11. In the second to fifth embodiments, the same or similar parts as those of the rod type electric cylinder 10 of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.
(Second embodiment)
As shown in FIG. 8, the rod-type electric cylinder 100 includes a tubular body 11, a cylinder rod 12, a support member 13, a drive unit 101, and a ball screw nut (driven member) 102.
The support member 13 is provided at an end portion including the open end 11b of the tubular body 11. The drive unit 101 is attached to the support member 13. The drive unit 101 includes drive force transmission means 105 that transmits the rotational force of the motor unit 84. The driving force transmitting means 105 includes a driving gear 106 rotatably connected to the motor unit 84 and a timing belt 107. The drive gear 106 is coaxially attached to the drive shaft 91 of the motor unit 84. A timing belt 107 is stretched around the drive gear 106 and the ball screw nut 102.

The ball screw nut 102 is provided in the vicinity of the opening end 11b in the cylindrical body 11, and is rotatably connected to a screw portion formed on the outer peripheral surface of the cylinder rod 12 via a ball. The ball screw nut 102 has driven teeth formed on its outer periphery, and the timing belt 107 is meshed with the driven teeth.
The drive gear 106 and the ball screw nut 102 are engaged with each other via the timing belt 107 by the timing belt 107 meshing with the drive teeth of the drive gear 106 and the driven teeth of the ball screw nut 102.

According to the rod type electric cylinder 100 of the second embodiment, the drive screw 106 is driven by the motor unit 84 to rotate the ball screw nut 102. By rotating the ball screw nut 102, the cylinder rod 12 can be moved forward and backward with respect to the cylindrical body 11.

(Third Embodiment)
As shown in FIG. 9, the rod-type electric cylinder 110 includes a tubular body 11, a cylinder rod 12, a support member 13, a drive unit 111, and a ball screw nut (driven member) 112.
The support member 13 is provided at an end portion including the open end 11b of the tubular body 11. The drive unit 111 is attached to the support member 13. The drive unit 111 includes a gear 114 as a drive force transmission unit that transmits the rotational force of the motor unit 84. The gear 114 is coaxially attached to the drive shaft 91 of the motor unit 84.

The ball screw nut 112 is provided in the cylindrical body 11 in the vicinity of the open end 11b, and is rotatably connected to a screw portion formed on the outer peripheral surface of the cylinder rod 12 via a ball. The ball screw nut 112 has driven teeth formed on its outer periphery. The gear 114 and the ball screw nut 112 are engaged with each other, so that the gear 114 and the ball screw nut 112 are engaged with each other.

According to the rod type electric cylinder 110 of the third embodiment, the ball screw nut 112 is rotated by driving the gear 114 by the motor unit 84. By rotating the ball screw nut 112, the cylinder rod 12 can be moved forward and backward with respect to the tubular body 11.

(Fourth Embodiment)
As shown in FIG. 10, the rod type electric cylinder 120 includes a cylinder body 11, a cylinder rod 12, a support member 13, a drive unit 121, and a rack (driven member) 122.
The support member 13 is provided at an end portion including the open end 11b of the tubular body 11. The drive unit 121 is attached to the support member 13. The drive unit 121 includes a pinion 124 as a drive force transmission unit that transmits the rotational force of the motor unit 84. The pinion 124 is coaxially attached to the drive shaft 91 of the motor unit 84.
A rack 122 is provided along a longitudinal direction (axial direction) on a part 12d of an outer peripheral surface (circumferential surface) 12c between the front end 12a and the rear end 12b of the cylinder rod 12. A pinion 124 is meshed with the rack 122.

According to the rod type electric cylinder 120 of the fourth embodiment, by driving the pinion 124 with the motor unit 84, the meshing position of the pinion 124 with respect to the longitudinal direction of the rack 122 is changed. As a result, the rack 122 is moved in the longitudinal direction, and the cylinder rod 12 is driven forward and backward in the longitudinal direction.

(Fifth Embodiment)
As shown in FIG. 11, the rod-type electric cylinder 130 includes a cylindrical body 11, a cylinder rod 12, a support member 13, a drive unit 131, and a magnet long piece (driven member) 132.
The support member 13 is provided at an end portion including the open end 11b of the tubular body 11. The drive unit 131 is attached to the support member 13. The drive unit 131 includes a magnet gear 134 as a drive force transmission unit that transmits the rotational force of the motor unit 84. The magnet gear 134 is coaxially attached to the drive shaft 91 of the motor unit 84, and the magnetic poles are arranged alternately along the circumferential direction of the drive shaft 91 (direction around the axis of the drive shaft 91).

A magnet long piece 132 in which magnetic poles are alternately arranged along the longitudinal direction (axial direction) is provided on a part 12d of an outer peripheral surface (circumferential surface) 12c between the front end 12a and the rear end 12b of the cylinder rod 12. There is. The magnet long piece 132 and the magnet gear 134 are arranged in a non-contact state, but the driving force of the motor unit 84 is transmitted to the magnet long piece 132 in a non-contact manner by the magnetic force.

According to the rod type electric cylinder 130 of the fifth embodiment, by driving the magnet gear 134 with the motor unit 84, the magnetic transmission position of the magnet gear 134 with respect to the longitudinal direction of the magnet long piece 132 is changed. As a result, the magnet long piece 132 is moved in the longitudinal direction, and the cylinder rod 12 is driven to move back and forth in the longitudinal direction.

The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and any design change that does not depart from the gist of the present invention can be applied to the present invention. included.
For example, in the above-described embodiment, the first half split portion 38 and the second half split portion 39 of the split fastening portion 26 are fastened with split fastening bolts 41 to split the end portion of the tubular body 11 including the open end 11b. The description has been given by exemplifying the case of being provided so as to be freely inserted into and removed from the portion 26, but the present invention is not limited to this. For example, the fastening portion 33 may have a complete two-divided half-divided structure or a three-divided or more divided structure instead of the split-tightened structure. Further, instead of fastening with the split tightening bolt 41, fastening with a clamp lever may be performed.

Claims

One with the open end and the other with the closed end,
A cylinder rod that is provided in the cylindrical body and can freely retract from the opening end;
A support member that is detachably attached to the tubular body,
A drive unit which is provided on the support member and which supplies a drive force for driving the cylinder rod to move back and forth;
A rod-type electric cylinder, comprising: a driven member that transmits the driving force of the driving unit to the cylinder rod.
The cylinder rod has a groove extending in the longitudinal direction on a part of its peripheral surface,
A timing belt as the driven member is provided in the groove,
The rod type electric cylinder according to claim 1, wherein a timing pulley provided in the drive unit is meshed with the timing belt to drive the cylinder rod forward and backward.
A ball screw nut as the driven member is provided in the vicinity of the opening end of the tubular body,
The rod type electric cylinder according to claim 1, wherein a driving force transmitting means provided in the drive unit is engaged with the ball screw nut to drive the cylinder rod forward and backward.
A rack as the driven member extending in the longitudinal direction is provided on a part of the peripheral surface of the cylinder rod,
The rod type electric cylinder according to claim 1, wherein a pinion provided in the drive unit is meshed with the rack to drive the cylinder rod forward and backward.
A magnet long piece as a driven member in which magnetic poles are alternately arranged along the longitudinal direction is provided on a part of the peripheral surface of the cylinder rod,
The rod type according to claim 1, wherein the magnet gear, which is provided in the drive unit and in which magnetic poles are alternately arranged along a circumferential direction, is non-contact transmitted with the magnet long piece to drive the cylinder rod forward and backward. Electric cylinder.
The guide member, which is provided at least at the open end in the cylinder body, holds the cylinder rod at the center of the cylinder body and assists the sliding of the cylinder rod accompanying the forward/backward drive. Rod type electric cylinder.
The guide member is
A fixed guide provided at the open end in the cylindrical body,
The rod type electric cylinder according to claim 6, further comprising: a movement guide provided inside the cylinder and provided at a rear end of the cylinder rod.
The rod type electric cylinder according to claim 1, wherein the support member includes a split fastening portion, and the tubular body is inserted into a split fastening hole in the split fastening portion.